1. Field of the Invention
The present invention relates to an optical waveguide array for the optical transmission of a signal or energy.
2. Description of Related Art
Known methods for manufacturing an optical waveguide array include a first method disclosed in Japanese Patent Publication No. 2629/77 and Patent Laid Open Nos. 69207/87 and 69208/87, which consists of bonding a reinforcing plate to an optical waveguide array body comprising cores and a clad layer and a second method wherein a large number of optical waveguides which have been formed in advance are arranged on a reinforcing plate, followed by adhesive bonding to complete an optical waveguide array, as disclosed in Japanese Patent Publication No. 5976/73.
However, in these known optical waveguide array manufacturing methods it is required to first form an optical waveguide array and thereafter bond a reinforcing material to the array. Thus, these methods require an additional bonding step and so are complicated. Also in the latter optical waveguide array manufacturing method, the need to arrange a large number of optical waveguides is very troublesome.
To avoid such complicated and troublesome steps, there sometimes is adopted a method generally called a 2P method to produce an optical waveguide array. According to the 2P method, clads and cores of optical waveguides are formed using a photocurable resin, then a reinforcing plate is brought into close contact with the photocurable resin which forms the clads, followed by light irradiation, to form an optical waveguide array.
However, the resins commonly used as materials for such a reinforcing plate, e.g., acrylic resins, polycarbonate resins and polystyrene resins, do not easily transmit a light of the wavelength necessary for the curing a photocurable resin. Consequently, the curing efficiency of the photocurable resin which forms clads and cores is low and the reinforcing plate is not strongly bonded to the optical waveguides resulting in a optical waveguide array of low reliability in both performance and quality. The manufacturing efficiency and yield are also low.